PUBLICATION
Autonomous Calcium Signaling in Human and Zebrafish Podocytes Controls Kidney Filtration Barrier Morphogenesis
- Authors
- Djenoune, L., Tomar, R., Dorison, A., Ghobrial, I., Schenk, H., Hegermann, J., Beverly-Staggs, L., Hidalgo-Gonzalez, A., Little, M.H., Drummond, I.A.
- ID
- ZDB-PUB-210430-3
- Date
- 2021
- Source
- Journal of the American Society of Nephrology : JASN 32(7): 1697-1712 (Journal)
- Registered Authors
- Djenoune, Lydia, Drummond, Iain
- Keywords
- calcium signaling, glomerulus, kidney organoid, organoid glomeruli, podocyte, zebrafish
- MeSH Terms
- none
- PubMed
- 33911000 Full text @ J. Am. Soc. Nephrol.
Citation
Djenoune, L., Tomar, R., Dorison, A., Ghobrial, I., Schenk, H., Hegermann, J., Beverly-Staggs, L., Hidalgo-Gonzalez, A., Little, M.H., Drummond, I.A. (2021) Autonomous Calcium Signaling in Human and Zebrafish Podocytes Controls Kidney Filtration Barrier Morphogenesis. Journal of the American Society of Nephrology : JASN. 32(7):1697-1712.
Abstract
Background Podocytes are critical to maintaining the glomerular filtration barrier, and mutations in nephrotic syndrome genes are known to affect podocyte calcium signaling. However, the role of calcium signaling during podocyte development remains unknown.
Methods We undertook live imaging of calcium signaling in developing podocytes, using zebrafish larvae and human kidney organoids. To evaluate calcium signaling during development and in response to channel blockers and genetic defects, the calcium biosensor GCaMP6s was expressed in zebrafish podocytes. We used electron microscopy to evaluate filtration barrier formation in zebrafish, and Fluo-4 to detect calcium signals in differentiating podocytes in human kidney organoids.
Results Immature zebrafish podocytes (2.5 days postfertilization) generated calcium transients that correlated with interactions with forming glomerular capillaries. Calcium transients persisted until 4 days postfertilization, and were absent after glomerular barrier formation was complete. We detected similar calcium transients in maturing human organoid glomeruli, suggesting a conserved mechanism. In both models, inhibitors of SERCA or IP3 receptor calcium-release channels blocked calcium transients in podocytes, whereas lanthanum was ineffective, indicating the calcium source is from intracellular podocyte endoplasmic-reticulum stores. Calcium transients were not affected by blocking heartbeat or by blocking development of endothelium or endoderm, and they persisted in isolated glomeruli, suggesting podocyte-autonomous calcium release. Inhibition of expression of phospholipase C-γ1, but not nephrin or phospholipase C-ε1, led to significantly decreased calcium activity. Finally, blocking calcium release affected glomerular shape and podocyte foot process formation, supporting the critical role of calcium signaling in glomerular morphogenesis.
Conclusions These findings establish podocyte cell-autonomous calcium signaling as a prominent and evolutionarily conserved feature of podocyte differentiation and demonstrate its requirement for podocyte foot process formation.
Genes / Markers
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Orthology
Engineered Foreign Genes
Mapping